Art of dentistry



Oct. 14, 1947 M. BERESIN ET AL 2,428,773

' ART OF DENTISTRY Original F i1ed Oct. 6, 1941 3 Sheets-Sheet 1 INVENTORS RRiS BER N BY VI OR E. BERE N ATTORNEYS @Ct 14, 1947. R sm ETAL 2,428,773

ART OF DENTISTRY 4 Original Filed 001;. e, 1941 s sneebs-sheet 2 F|G.IO v FIGH INVENZORS' MORRIS BERESIN BY VICTOR E. BERE SIN A TTORNEYS Oct. 14, 1947. 5 N ETAL I 2,428,773

ART OF DEN'I'IS TRY Original Filed 001;; s, 1941 a Sheets-Sheet :5

INVENTORS MORRIS BERESIN 7 BY VICTORE.BERESIN Cam m ATTORNEYS I atented Oct. 1 4, 1947 ART: OF DENTISTRY Morris B'eresin and Victor E. Beresi'ri,

' y Pliilad'elphia,.la. Continuation of; application Seria1 No'.-413,76(i,

October 6, 1941.. This applicatiomEebnuary'l, 1.944;. Serial'No; 520,602

This invention relatesto the art of dentistry, and has particular reference to that phase. of the art which concerns itself with the taking of im-' pressions for use in the construction of dentures.

By way of introduction, it may be statedtliat an.-

impression may be either of the entire maxilla (upper jaw) or of a portion thereoflor. of. the entire mandible (lower jaw) or ofa'portion thereof. An impression may also be of a partially edentulous jaw, Where some'of the natural-teeth stillremain, or ofrafully edentulous jaw-,. where all of. the natural teeth have been lost,

Inthe case of a partially edentulous j aw,,there:

are two entirely different anatomic and physiological structures. The ridge consists in part: of

tissues, softand pliable, which are easily displaced.- or distorted. The teeth, on the other hand, arecomposed of uniformlyshard structure. with'a spe cific. anatomic. form. In. making an. impression for a partially edentulousmouth; it is thought to. be. clear that the procedure andmaterial best suited for an impression of the teeth-islunsuited. for an impression of, the ridge. Conversely, the material and. procedure best suited: for animpression ofthe ridgeis not Well suited for an impressionof the teeth..

A similar situation existsiin the making of fullyf .In: the. case of; the

edentulous impressions: edentulous jaw, there are also two distinctly different areas which must be treated-separately, by: different processes and materials in. order; to obtain suction andadhesion and.stability;.whichare essential. for the functional. retention of, full,

dentures. The impression .ofxtheperipheral section, commonly known as the flexion line, requires, a certain amount of. pressure in: order to obtain:-

suctionin the final denture whereas the horizontal or denture bearing areas require non-presssure and non-displacement of tissue in ordertoobtain adhesion or perfect adaptation of the denture base to the tissues. If the. soft tissues:

of the denture bearing areas are displaced or. dis-; torted, the impression will not be an accurateand faithful reproduction.

Although, as above stated, the making of an impression, whether for a partially we fully.- edentulous jaw, requires two diiTerent materials and two different procedures, both procedures'and materials must be embodied in a single process and a unitary impression. This has long. constituted a difficult problem in the construction of dental restorations.

An important object of this invention is to overcome the above stated difficulty, that is-to' solve-the" problem of making. a completezand-ac- 4 Claims; (Cl. 32-17).

curate reproduction of ajaw, whether. partially or fully. edentulous, by asinglep'rocess' andjina unitary impression.

The. essence of the: inventionwliich renders the foregoing object" possible of accomplishment residesirrthe. provision of an impression tray. of"

novel' and unique. form and construction.

Briefly stated; the dental'tray ofthe invention is a composite tray consisting of a main or peripheralsectionand a subsidiary section,.the main" section conforminggenerally'to the area of'wl'ii'ch the-impression is to. be t'alien (maxilla or. mandible and surrounding tissues), and having a cut-out portion to expose the. remainingteethin a partially edentulous jaw, the crest of the ridge in the mandibular edentulous jaw, orthepalate and the crest of the ridge'in the maxillary edentulous j.aw,.the subsidiary section constituting a cover for the cut-out portion and'ltieing adapted to be unitedto the main section o'f'the'tray to form a continuous. tray'.

Briefly" stated; the impression tray of'the invention may be used as follow's'z First an impression is taken of "the jaw or oftlie portion. ofthe jaw. for which thedenture is to bema'de, usingthe main or peripheral'section of the-tray and one type of'imp-re's'sion material;

Then the subsidiary section of "the tray is'affixed' to the. mainsection, and theimpression is completed, using another typelof'iinpression' material.

In the'case of partial denture prosthesis, the first impression is't'aken witlda material suitable for an impressionof thev ridge and the second impression is taken withpressure-exerting plastic.

suitable for. .acorrect reproduction of. the teeth. In the case of full denture prosthesis, theifirstiinpression is takenzwith aplastic materialiwhich exerts pressure and the second impression. isv

takemwith a very. soft: fluent materialwhich does not exert substantial pressure.

The-impression taken with the subsidiary section; of 1 the tray. may. be performed. by inj ecting or spraying a plasticor fluid material.

The composite tray, with its twoestep p ocedure. employing the injectionor sprayingmetho'd, may

be used to take an impressionfor any type of dental. restoration. In addition to its. application for partial and full denture impression, it may also be used for making impressions of inlays, crowns, bridges, both stationary-andremov able etc.

At thispoint, it may be'stated' thatwe have foundthe; spraying technique to be particularly suitable for obtaining impressions of edentulous jaws, as'ait entirelyavoids the: displacement. anddistortion of soft tissues. We have also found the spraying technique to be very advantageous for impressions which require absolute accuracy and precision, such as inlays and jacket crowns.

Referring now to the drawings, wherein several or the purforms of impression trays are shown f Figure 2 is a similar view of the main or peripheral section of said tray;

Figure 3 is a perspective view, partly away, of the subsidiary section of said tray;

Figure '1, said tray being shown in normal position for taking an impression;

Figure 5 is a similar view of a modified form of maxilla tray, in which the subsidiary section is secured to the main section by means of a lockin device, which also serves as a handle for the composite tray;

Figure 6 is a perspective view of the combined locking means and handle;

Figure 7 is a view in perspective, partly broken away, of a modified form of tray for 'taking'an impression of the maxilla for partial denture prosthesis; V

Figure 8 is a view in perspective, partly broken away, of a tray for taking the'impression of the mandible (lower Jaw) for partial denture prosthesis;

Figure 9 is a similar view of a modified form of such tray;

Figure 10 is an end view of the subsidiary section of said tray;

Figure 11 is a cross-sectional view taken on line 1 |-Il of Figure 9;

Figure 12 is a transverse section through a part of a human head illustrating the injection process for applying a plastic material in the subsidiary portion of an impression tray for partial denture prosthesis;

, Figure 13 is a perspective view of a tray for taking the impression of the maxilla for full denture prosthesis, the tray being shownupside down; 7 V

Figure 14 is a similar view of the main or pe ripheral portion of the tray; V

Figure 15 is a similar view of the subsidiarysection of said tray;

Figure 16 is a perspective viewof a tray for taking the impression of the mandible for full" denture prosthesis, the tray being shown in 'nor mal position; 7

Figure 17 is a similar view of the main or mripheral section of the tray; and

-Figure 18 is a similar view of the subsidiary section of the tray.

Reference will now be had to Figures 1 to 7 broken Figure 4 is a perspective 'view of the tray of inafter appear, receives the impression material, and may be termed the saddle of the tray.

The main section has a cut-out portion 4 to entirely expose the remaining teeth. The section 3, which may for convenience be termed the subsidiary section, constitutes a hollow cover for the cut-out portionsof the main section of the tray and is adapted to be united to the main section of thetray to form a continuous tray. The subsidiary section 3 is of such size as to receive the'remaining teeth which extend through the cut-out portion 4 of the main section 2. The main section may advantageously be provided about the 'cut-out portion with a continuous vertical rim 5 having substantially the same peripheral con-- figuration as the vertical walls of the subsidiary section, so that the subsidiary section will fit snugly to the main section as shown in Figures 1 and 4. A second rim 6 ofsomewhat lesser height than the rim 5 may be. provided about the rim 5, forming a step upon which the subsidiary section may rest.

The subsidiary section 3- is shown provided on 'its top with a vent hole 1, for a purpose to'be hereinafter pointed out. The section 3 is also provided with a nozzle 8 also for a purpose to be pointed out.

The composite tray maybe fabricated out of i any suitable material such as metalor artificial inclusive, wherein are shown several forms of' 3.1 The section 2, whichmay for convenience be termed themain or peripheral section conforms generally to the entire area of which the impression is to be taken; i. e. the outer periphery of the maxilla and thepalate of the mouth.

'The' concavity inthe main section',-as will herementioned aluminum, tin and steel.

As examples'of suitable metals may be As an indication of the many suitable plastic materials may be mentioned the cellulose plastics such as Celplastic.

luloid, "Lumerith and Tenite, the phenolic resins such as Durlte and Bakelite, the urea resins such as Beetle and Plaskon, the vinyl resins such as Vinylite, and the acrylate resinssuch as Acryloid, Lucite and Plexiglas Both sections may be made of the same material f or of different materials.

The main section may advantageously'be made of pliable 'or flexible material, so that it can be made to conform as closely as may be desired to the jaw of the particular patient being treated.

The tray shown in Figure 5 differs from the one just described in being provided with a com v bined securing means and handle for thetwo sections.

of the tray, are designated as 2 and 3' respec-j Referring to Figure 5, the twosections tively. The air vent is'hidden from view, and, the nozzle is denoted by 8. i The combined securing means and handle is denoted generally by I0, and is provided with a vertical securing portion ii and a' horizontal han-. The main section Z'of. the tray is shown provided with a horizontal ear or loop I3, and the subsidiary section is shown provided j dle portion [2.

witha horizontal loop or ear I4. The two ears are in vertical alinement, and the vertical securing portion I l is adapted to be passed through the two ears, thereby securing the two sections of the tray together. When the sections are thus united togethenthe composite tray may be handled as a unit by means of the handle portion [2,

In the trays thus far described, the cut-out por- ,tions were disposed centrally of the outer periphery of the tray. Such a tray is designed to take 7 an impression of a jaw containing several front teeth. In Figure 7, the cut-out portion of the Jaw are missing. 7 V J 7 V Figure "7, the main portionof the'tray is] tray extends from the center of the outer periphery t one end of the tray, 'and the'subsidiary section corresponds thereto.

able in casethe teeth'on only oneside 0f the Such a tray is suitdenoted by 211, the subsidiary section by. 3a, the

air vent by 1a and the nozzle by 8a.

At this point, it may be stated that the cutout portion of the tray may correspond in size and in position to as many or as few teeth as.

may be remaining in the mouth of a patient..

trays for taking an impression of the mandibularjawcontaining several teeth. Referring to Figure 8, the tray is seen as consisting of a main or peripheral section 2| and a subsidiary portion 22. The section 2| conforms generally to the mandible and the surrounding tissues, and is provided with a cut-out portion to expose the remaining teeth, said portion being covered by the subsidiary portion 22. The subsidiary portion is provided with an air vent 23 and with a nozzle 24, and is secured to the main portion of the tray by means of the element 25. This element, as previously stated, has a vertical securing portion 26, which passes through cooper-- at-ing loops 2'! and 28 provided on the two sect-ions, and a horizontal handle portion 29.

Referring-now to Figure 9, it will be seen that the tray therein illustrated consists of a main orperipheral section 3! and a subsidiary section 32; The main section comprises two similar end portions 33- and 34 connected by means of a thin web 35. The-end portions 33 and 34 are provided in; their lower surface with a groove 34a to receive the impression material, said groove constituting the saddle 0f the tray. The subsidiary section constitutes a cover for the space between the two end portions of the main section and is hollow so as to receive the remaining teeth in the area of' which the impression is to be made. A lug 36 isprovidedat each end of the subsidiary section;

these lugs fitting into corresponding grooves 31,,

thin web In order to secure the subsidiary section to the main section, a pin 40 may be passed throughalined apertures in the main section and thelugs. As in the previously described embodiments, the subsidiary section is provided with an air vent 4i and a nozzle 42',

The following is a suggested procedure for taking an impression of a partially edentulous. jaw using the composite tray of the invention:

Snap impressions and bites are taken, models are. poured, and the case is articulated as in the conventional practice, in order to facilitate the selection of a, suitable tray for the patient being treated; After the proper tray has been selected and'adjusted, the subsidiary section is detached from the main section so that it will not interfere with .the taking of an accurate impression of the ridge of the .jaw. At this point, it is to be noted that provision should be made on the main section of the tray for either a central bearing point or a bite, block. This is necessary so that the main section of the tray can be readily reseated in exactly the. same position each time and held by the opposing teeth during muscle trimming. I

In taking the impression of the ridge, we prefer to utilize modelling compound, because it is correctible and can be repeatedly reinserted in the mouth, and can laterbemodified to obviate any The modelling compound is softened, and;

placed in the saddle portion; of; the main section of the: tray. The. main section is. inserted; in. the mouth, firm-1y: seated and. roughly musclel trimmed. After chilling, the tray is removed; fromthe mouth: andithe. modelling. compound re-v heated. Themain section of the tray is again inserted in. the mouth and held. inv positiom. This procedure is: continued until perfect stability, adaptation, and muscle trimming are ob:- tained'. As willbeunderstood by thosesskilledin the: dental art care must be taken that. al1.positive areas are included in the impression, and. that. there is" no impingement onthe 111118016311.- tach'ments.

At this stage, there may be some displacement. or distortion. of the tissues, due to the fact that the modelling: compound is considerably firmer:

than the tissues. This can be corrected as. in. the? conventional. procedure by scraping away; a very minute layer of compound from the crest of therridge, replacingit with molten-wax, andarein sertingthe tray in the mouth.

After the impression of the ridges. has been satisfactorily completed, the subsidiary section is, secured tothemain section of the tray, thereby forming; acontinuous tray,zandan impression is taken; using; the entire tray. In practice. it has been .found; preferable to inject the secondary impressionmaterial, which may be a hydrocol10id,. iIItOgthGSUbSldifiIY section of the, tray bymeans of a suitable form of syringe. shown in; Figure. 12-v of; thedrawing. The orifice or the syringes. is inserted into, the nozzle 8. and the; hydrocolloid is forcedinto the tray, the, air andythe excess of. plastic being forcedaout through-1 the-vent,1-..

At, thiS, 12Qint,'it willgbe understood, that if. the saddle portion: of the tray has been properly muscle trimmed, and the tray has been inserted in the mouth in proper position, a perfect, pe ripheral seal is formed and the hydrocolloid material is effectiyelyprevented from seeping under thersaddle. After the tray is chilled in the mouth for about five minutes, thetray is taken from the. mouth. If the procedure is properly carried out, the-primaryand-secondary. impressions will be. in

accurate relationshipto each other, forming one.

ations withoutany danger of the twosectionsbes ingr separated.

Reference will now be had to. the impression.

tray shown in Figures 13, 14 and 15. This tray 50, which is designed. to take an impression of; the upper edentulous jaw, consists of the. two, separable sections 5| and 52. The sections 5|, which may for convenience be termed the main or peripheral section, includes the area from. the flexion line or the mucco-buccal fold of the maxilla to the crest of the ridge as well as the area at the junction of the hard and soft palate, and is provided with the central cut-away portion 53. The section 52, which may be termed the "subsidiary or palatal section is of a shape and'size to fit the cut-away portion, thereby'proe viding a space below the palate of the patient treated.

The inner periphery of the main section may be provided with a'vertical rim 54 which is of" the same configuration as the vertical wall of" the subsidiary section, so that the two sections This operation. is

may be snuglyfitted together. The subsidiary.

section may be provided with one ormore air vents 55 and a nozzle 56.

f The tray' 60 shown in Figures 16, 17' and i8 is for a lower edentulous jaw, and consists of the main or peripheral section 6| and the subsidiary or ridge section 62. The peripheral section includes the area of the flexion'line just short of the crest of the ridge, the retro-molar triangle.

and lingually the attachmentsof the fioor of mouth to the ridge. Th peripheral sectionis provided with a cut-out portion 63, about which may be provided a vertical rim 64 to which the subsidiary section may be snugly fitted. The

reference numeral 65 denotes a number of spaced thin webs bridging the cut-out portion. These webs serve to partially support the tray on the gums of the patient. As shown, the subsidiary portion may be provided with one or more air vents 6E and a nozzle 61.

The dental trays shown in Figures 13 to 18 may be used in substantially the same manneras has been described in reference to the partially edentulous trays. A variation consists in using spraying method instead of an injection method for the secondary impression. V

' The following is a suggested procedure:

The primary impression is taken in substantially the same manner as has been previously described. Then into the cut-out portion of the main section, while it is in proper position in. the v patients mouth, there is sprayed by means of a suitable device (spraying gun) a molten wax dispersion or one of the many dental pastes avail able on th market. It is sufiicientto produce a spray coating about 2 or 3 millimeters in thick ness. On top of the sprayed material, there is then poured a dental plaster or artificial stone. The subsidiary section of the tray is then united e to the main section, the excess plaster or arti- The ficial stone escaping from the air vents. plaster or artificial stoneserves to reinforce the sprayed coating. 7 v

' A permissible variation consists in placing the subsidiary section of the tray in positionf be fore the dental plaster or artificial stone isapplied. In such case, the plaster or" stone in liquid form may be injected into the subsidiary section by means of a syringe.

It will be understood from the foregoing dis;

closure that we hav provided a very simple and relatively inexpensive dental impression tray,

which has the decided advantage over pre viously known orused trays in being capable .of producing a. faithful and accurate reproduction of all the details of a jaw, either partially or fully edentulous, or of a desired'portion of .such jaw, including both hard and soft areas, with-. out any undue displacement or distortion ,of the soft tissues. Another advantage of our novel tray is that it effectively confines the plastic material to the areas of which the impression is being taken, thereby preventing spilling of'the plastic.

material over the mouth or into the throat of the patient. v I V p V 'In conclusion, it may be stated that various other modifications of the-herein disclosdinvention'may be made,'and that itis therefore to be understood that the invention. is not to be plication Serial No. 413,760; filedjOctober 6, 1941.

We claim:

1. A dental impression tray for a partially eden-J tulous jaw, said tray consisting. of a main section provided with a peripheral concavity con-forming generally to "the areaof the jaw of which the impression is to be taken,: said peripheral concavity being provided with an opening to, permit the re-y maining teethto extend out from said main sec tion, and a hollow'removable cover forsaid opening, said cover being secured to said main section by frictionally coacting flanges, and being adapted to completely enclose said remaining teeth and forming with said main section a continuous concavity for the reception of impression material,

whereby a unitary impression of said jaw may be made, said hollow cover being provided with a nozzle for the introduction of impression materialv and with a vent-hole for the escape of air and excess impression material. 7

2. A dental impression tray for a fully edentu lous jaw, said tray consisting of a main section provided with a peripheral concavity conforming generally to the area of the jaw of which the impression is to be made, said peripheral concavity a'vent hole for the escape of air.

3. A dental impression trayconsisting of amain section provided with a peripheral concavity con forming generally to the area of the jaw of which the impression is to be rnadeQsaidw peripheral concavity being provided with an. opening to expose a portion of the area of which the impression is to be made; and a hollow removable coverfor said opening; said hollow cover being secured to said main section by frictionally coacting flanges, and constituting a subsidiary section of said tray and forming with said main section a continuous concavity for the receptionof impression material, whereby a unitary impression of said jawmay' be 7 made, said subsidiary section'being provided with a nozzle through which impression material may be introduced into the trayand with a ventv hole for the escape of air.

4. A dental impression tray. consisting of a main section provided with a peripheral concavity conforminggenerally to the area of the'jaw of which the impression is to be made, said peripheral concavity being provided with an'opening' to expose" a portion of the area'of which the impression is v to be made', and a hollow cover for said opening,

said hollow cover constituting a subsidiary section ofsaid tray and forming with said main section a continuous concavity for the reception of impression material, whereby a unitary impression of saidjaw maybe made, said. tray being provided with means to secure the sections togetherg said considered as being limited by the specific'examples herein given as illustrative of theinvention, except as-maybe necessitated by thestateof the prior art.

This application is a continuation; of -apmeans consisting of registering loops on said main section and said subsidiary section and a tonguelike member passing through said loops, said tongue-like member being provided'with a handle to facilitate handling of said tray.

MORRIS BERESTKTT VICTOR EQBER'ESIN nc s enj ns. pa er;

Number REFERENCES CITED 1,509,376 The following references are of record in the 1,185,518 file of this patent: 987,063 UNITED STATES PATENTS 5 2,096,375

Number Name Date 2,155,334 Sitkin et a1 April 18, 1937 Number 1,499,973 Douglass July 1, 1924 206,913

10 Name Date Rodgers Sept. 23, 1924 Marcoux May 30, 1916 Greene Mar. 14, 1911 Jones Oct. 19, 1937 FOREIGN PATENTS Country Date Germany Feb. 27, 1908 

